The alteration of the color of keratinous fibers, in particular human hair, by the application of hair dyes is well known. In order to provide the consumer with the hair color and the intensity of color desired, a very complex chemical process is utilized. Non permanent hair colorant formulations typically comprise a non permanent dye such as direct dyes and or pigments which are deposited on to the surface of the hair and are gradually washed out over successive washing cycles. Permanent hair colorant formulations typically comprise oxidative hair dye precursors, which can diffuse into the hair through the cuticle and into the cortex where they can then react with each other and suitable oxidising agents to form the end dye molecules. Due to the large size of these resultant molecules they are unable to readily diffuse out of the hair during subsequent washing with water and/or detergents; hence delivering the consumer-desired permanency of color. The reaction typically takes place in an aggressive environment at approximately pH 9 to 11 in the presence of an alkalizing agent and in the presence of an oxidizing agent. Moreover, the consumer repeats this process regularly in order to maintain the desired hair color shade and the intensity of color and to ensure continual, even coverage of the hair including coverage of new hair growth. Hair bleaching and highlighting compositions further typically utilize a strong oxidizing agent such as hydrogen peroxide and a persulphate salt in order to lighten the hair colour.
However, despite the fact that commercial hair colorant products have been available for many years, the products still exhibit a number of consumer-related deficiencies. The process of applying the hair coloring or bleaching composition to the consumer's hair by the consumers themselves is not a simple process. In particular, the application of hair colorant products is still a relatively time consuming process and it may take the consumer over an hour to mix, apply, wait for the color to develop and remove the product, before even drying and styling. Since for most consumers the hair coloring process is a regular part of their beauty routine it would thus be highly desirable if the time required to dye the hair could be reduced.
Furthermore, the application of the hair colorant or bleach also requires dexterity and patience by the consumer to ensure a satisfactory end result and to prevent any accidental spillages on the consumer's skin, clothing or bathroom furniture. Typically the consumer engages in a complex process to apply the composition to ensure an even color outcome. This is particularly difficult if the hair has been previously colored. In such circumstances the consumer typically firstly applies the composition to the entire root area of the head to cover any regrowth and then subsequently, often by the use of a comb, pulls the composition along the entire length of the hair to the tips to ensure coverage of all of the hair to thus ensure an even end colour result. However the presence of these compositions on the hair typically contributes towards the tangling of the hair, thus making the combing through of the compositions difficult and often even painful. Moreover, the application of the composition through tangled hair may also cause small amounts of the composition to be deposited on the consumer's skin, clothing and bathroom furniture. Consequently, a relatively large amount of the composition is also required in order to satisfactorily cover the entire head of hair.
Many attempts have been made to improve the ease of application of hair colorants on the hair of the consumer. These have typically resided in the development of devices to use in combination with the colorant dispenser, such as comb type applicators as described for example in WO9926510, WO9926511 and WO9926596. However such devices are not only expensive to produce, but also, do not solve the problem of improved ease of application from root to tip of the hair.
It has now been surprisingly found that by the use of a specific pre-treatment method whereby a pre-treatment composition is applied to the hair without rinsing this composition, prior to the application of a hair bleaching or colouring application, allows for the simpler and faster application of the colourant or bleaching composition. In particular, the compositions are easier to apply and reduce the amount of tangled hair generated, associated with the subsequent application of the hair colourant or bleaching composition. Thus this improves the even application of the composition onto the hair. Moreover, the method also requires less colorant or bleaching composition in order to obtain a good color result. Another benefit of the present invention is that the condition of the hair immediately after the bleaching or colouring process is significantly improved, thus negating the requirement of a post bleaching or colourant conditioner application.
The use of pre-treatment compositions for hair coloring compositions is described in the art. US2003/0121109 and US2003/0126692 describe processes for the pre-treatment of keratinous fibers to be colored comprising specified aminosilicones. The pre-treatment compositions may be rinsed off or retained on the fibers prior to colouring and provide improved dye deposition on the fibers and reduce the degradation of the fibers.